TIL: Using git check-ignore to debug your .gitignore
Here’s a useful thing I learnt today: you can use git check-ignore to debug your gitignore rules and find out why a particular file is (or isn’t) being ignored. It knows all the places where gitignore rules might be defined, and how Git decides between conflicting rules.
git check-ignore --verbose <PATH>, you can see which rule applies to a given path, and where that rule is defined.
There are times I’d have found this very handy!
A few examples:
If a file is being ignored and you don’t know why, it can show you which line of the .gitignore is causing it to be ignored.
$ git check-ignore --verbose pictures.zip .gitignore:116:*.zip pictures.zip
If a file isn’t being ignored and you think it should be, it can show you which rule is negating your ignore rule:
$ git check-ignore --verbose pictures/cats.zip pictures/.gitignore:17:!cats.zip pictures/cats.zip
Notice that it looks in .gitignore files that aren’t in the root of the repo (the sort of thing I often forget about).
It can even look in your
.git/info/exclude, a place for per-clone ignore rules that you don’t want to keep in the repository:
$ git check-ignore --verbose scripts/alex/downloader.py .git/info/exclude:7:scripts/alex/*.py scripts/alex/downloader.py